Patent attributes
A therapeutic device to release a therapeutic agent comprises a porous structure coupled to a container comprising a reservoir. The reservoir comprises a volume sized to release therapeutic amounts of the therapeutic agent for an extended time when coupled to the porous structure and implanted in the patient. The porous structure may comprise a first side coupled to the reservoir and a second side to couple to the patient to release the therapeutic agent. A plurality of interconnecting channels can extend from the first side to the second side so as to connect a first a plurality of openings on the first side with a second plurality of openings on the second side. Each of the openings on the first side can be connected to each of the openings on the second side with the plurality of interconnecting channels, such that the rate of release of the therapeutic agent can be substantially maintained when one or more of the openings is blocked, for example with particles, cells, bacteria or tissue when the device is implanted for an extended time. The length of the channels extending from the first side to the second side may comprise an effective length greater than a distance across the porous structure from the first side to the second side. The therapeutic device many comprise an expandable retention structure and an expandable reservoir, such that the device can be delivered from a lumen of a delivery device and expand when positioned in the patient. The therapeutic device may comprises a penetrable barrier to inject therapeutic agent into the device when implanted in the patient.